1. Field of the Invention
The present invention relates to a steam turbine power plant and a method for activating the steam turbine power plant.
2. Description of the Related Art
Renewable energy for power generation is typified by wind power generation and solar power generation. For a power plant using such renewable energy, the amount of electric power generated from renewable energy greatly varies depending on seasons, weather, and the like. Thus, this kind of power plant provided with a steam turbine needs to further reduce the time it takes for activation in order to suppress a variation in the power generation amount for stabilization of the power plant.
Since, upon the activation of the power plant, steam flowing in the steam turbine rapidly increase in temperature and flow rate, the surface of a turbine rotor rapidly increases in temperature accordingly, compared with the inside of the turbine rotor. As a result, the turbine rotor has a large temperature gradient in a radius direction thereof, followed by suffering increased thermal stress. Excessive thermal stress may reduce the life of the turbine rotor; therefore activation control need be exercised so as to prevent the increased thermal stress from exceeding a preset limit.
As this kind of activation control method, JP-2009-281248-A describes a method for activating a steam turbine at a high speed by calculating, in predictive manner, thermal stress applied for a certain period of time from the present to the future and determining an operational amount of a plant such that the thermal stress is controlled to a value equal to or lower than a limit.